<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="utf-8">
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0"/>
    <title>输入框</title>
    <link href="css/bootstrap.css" rel="stylesheet">
    <style>
        body{
            padding: 10px;
        }
    </style>
</head>
<body>
<div class="container">
    <div class="input-group input-group-lg">
        <span class="input-group-addon">@</span>
        <input type="text" class="form-control" placeholder="Username">
    </div>
    <br/>
    <!--右边-->
    <div class="input-group input-group-sm">
        <input type="text" class="form-control" placeholder="请输入要搜索的内容" >
        <span class="input-group-addon" >
            百度一下
        </span>
    </div>

</div>


</body>
</html>